1. Field of the Invention
The invention relates to the writing of information to and the reading of information from optical discs.
2. Description of the Related Art
Optical discs, such as the compact disc (CD) and digital versatile disc (DVD), are an inexpensive and popular medium for the storage and distribution of digital information. Like many digital storage/distribution media, optical discs are susceptible to unauthorized use. For example, a first person purchases a CD containing a computer program and installs the program on a computer, typically an authorized use. However, the first person then gives the disc to a second person, who proceeds to install the program on a second computer, typically an unauthorized use. The author/copyright owner might receive no compensation for the unauthorized use of his or her copyrighted material. Thus, there is an ongoing need for mechanisms that prevent the unauthorized use of optical discs.